Metal Detecting

Looking for a light project to teach young hackers some very basic electronics? Here’s a quick and easy weekend project, a simple metal detector!

We all know 555 timers are very useful and pop up in a wide range of projects, but did you know a metal detector is one of them? [vonPongrac] stumbled upon this handy guide, a free eBook on 50 555 Circuits, which contains many cool project ideas, including a simple metal detector circuit. It’s a very basic concept that uses a coil of copper wire as a home-made choke — when metal or a magnet comes near the coil, it varies the output frequency, and the 555 timer in turn, varies the output sound, alerting you of the presence of something metal nearby.

After the break there’s a video of it during its testing phases. If you don’t have a 555 on hand (tisk tisk) but still want to have some treasure hunting fun you can also build one based on an Arduino.